Decomposition of metal carbonyls

ABSTRACT

Fluid bed reactors for decomposing metal carbonyls and comprising a vertically disposed, elongated vessel for confining a bed of fluidized particulate material are provided with heating coils, that can be heat exchange coils through which heating fluid is passed or electrical resistance heating coils, in the lower part of the reactor and fluidized bed so that the lower portion of the fluidized bed functions as a heating region while the upper portion functions as a decomposing zone. The lower and upper portions of the fluidized bed are volumetrically proportioned to provide substantially equal gas velocities to promote conveyance of heated particulate material from the heating region to the decomposing region. A process for decomposing metal carbonyls is also disclosed in which separate heating and decomposing regions in a fluidized bed are established and a metal carbonyl is introduced into the decomposing region via a water-cooled lance to be decomposed on heated particulate material.

O United States Patent 11 1 1111 3,839,077 Robinson 1 51 Oct. '1, 1974 DECOMPOSITION OF METAL CARBONYLS [75] Inventor: Ronald Dale Robinson, Port 'm Exam 1er' M1Chae] sofoc,leous Colbome, Ontario, Canada Assistant ExammerBernard D. Planalto {73] Assignee: The International Nickel Company, [57] ABSTRACT New York Fluid bed reactors for decomposing metal carbonyls [22] Filed: June 21, 1971 and comprising a vertically disposed, elongated vessel I for confining a bed of fluidized particulate material [21] Appl' 15435: are provided with heating coils, that can be heat exchange coils through which heating fluid is passed or [30] Foreign Application Priority Data electrical resistance heating coils, in the lower part of J 1 8, 1970 c d 87,694 the reactor and fluldlzed bed that h u y ana a of the fluidized bed functions as a heating region while [52] s CL." R 1 7/ G 6 117/100 M the upper portion functions 35 a decomposing zone. 1 17/106 1 fi 2 1 18/48 1 18/303 The lower and upper portions of the fluidized bed are 118/306 volumetrically proportioned to provide substantially 5 1; ""i z 11/02 equal gas velocities to promote conveyance of heated [58] Field 6 M DIG 6 particulate material from the heating region to the dei18/48 3 composing region. A process for decomposing metal carbonyls is also disclosed in which separate heating [56] References Cited and decomposing regions in a fluidized bed are established and a metal carbonyl is introduced into the de- UNITED STATES PATENTS composing region via a water-cooled lance to be de- 222 x02 e -z-a-l composed on heated particulate material.

315941215 7 1971 Wakefield 117 1072 x 9 Claims, 2 Drawing Figures 3,605,685 9/1971 West et al 118/48 1 DECOMPOSITION OF METAL CARBONYLS The present invention is particularly useful for decomposing metal carbonyls, such as nickel tetracarbonyl or iron pentacarbonyl, and will be described in conjunction therewith; but the present invention has much wider applicability. For example, the present invention can be employed to coat particulate material with a vaporous component by condensing and solidifying the vaporous component on the particulate material.

Proposing to take advantage of the excellent gassolid contact inherent in fluidized beds, various processes for thermally decomposing metal carbonyls in fluid bed reactors have been developed. The thermal decomposition of metal carbonyls is an endothermic process, and the problem most commonlyencountered has been the manner in which heat is supplied to the fluid bed reactor.

Carbon monoxide, one of the products of metal carbonyl decomposition, is also employed to dilute metal carbonyls in order that decomposition can be more easily controlled. At temperatures below about l,300F. carbon monoxide is unstable and disproportionates to carbon dioxide and elemental carbon. The rate of carbon monoxide disproportionation is imperceptible at room temperature but accelerates with increasing temperatures and at metal carbonyl decomposition temperatures the rate of disproportionation is sufficiently high to cause carbon contamination problems. Thus, localized regions of high temperatures within the decomposition chamber must be avoided if carbon contamination of the carbonyl metal product is to be minimized.

It has been suggested that fluidized beds be indirectly heated by supplying heat through the reactor walls. Although fluidized beds provide excellent heat transfer, particularly between the suspended particulate material and the fluidizing gas, it has been found thatheat transfer from the reactor walls to the fluidized bed is inefficient. It has been postulated'that a thin gaseous film or lamellar flow of gases is created between the reactor walls and the fluidized bed and that the film or lamellar flow inhibits heat transfer from the reactor wall to the fluidized bed. In some instances, measurable temperature differentials of 80F. and higher have been recorded. If, during the thermal decomposition of metal carbonyls, the walls of a fluid bed reactor must be maintained at unduly high temperatures in order to supply the requisite heat for the endothermic decomposition, the poss'iblity of carbon monoxide disproportionation is increased. In fact, it has been noted in the prior art that carbon associated with carbonyl metal powders produced in fluid bed reactors can be traced to the higher temperatures at the reactor walls.

In order to overcome the problems associated with inefficient heat transfer through reactor walls, it has been suggested to preheat the particulate material to be coated and/or the fluidizing gas, e-.g., carbon monoxide. It has also been suggested that the particulate material be maintainedin the fluidized state and at proper temperature by employing apreheated suspension of particulate material in a fluidizing gas. Merely preheating the fluidizing gas outside of the fluid bed reactor offers no guarantee that the carbonyl metal product will be carbon free since carbon monoxide can disproportionate in the preheater and the disproportionation products can be carried into the reactor with the same undesired result as though the disproportionation had occurred in the fluid bed reactor. Moreover, preheating the fluidizing gas is quite inefficient because the heat capacity of gases are volumetrically far less than the heat capacity of solids. Preheating the particulate material creates burdensome materials-handling problems and requires that particulate material to be continually removed from the reactor, not in response to the production rate, but wholly in response to the heat requirements. The use of a preheated suspension of particulate material in the fluidizing gas to supply heat, although the expedient works reasonably well, requires additional materials-handling equipment and more floor space Ihis expedient, not closely controlled, can

produce carbon via carbon madame disproportion ation in the the preheater. Although attempts were made to avoid the foregoing problems and disadvantages, none, as far as I am aware, was entirely successful when carried into commercial practice on an industrial scale.

It has now been discovered that metal carbonyls, including nickel carbonyl and iron carbonyl, can be thermally decomposed in specially designed fluid bed reactors while the production of carbon via the disproportionation of carbon monoxide is minimized.

It is an object of the present invention to provide a process for thermally decomposing metal carbonyls in fluid bed reactors.

Another object of thepresent invention is the production of carbonyl metal powders in fluid bed reactors while minimizing carbon contamination.

Yet another object of the present invention is the provision of a fluid bed reactor especially adapted for the decomposition of metal carbonyls.

An even further object of the present invention is to provide a method for controlling the heat input to a fluid bed reactor.

Other objects and advantages will become apparent from the following description taken in conjunction with the drawings in which:

FIG. 1 is a longitudinal section of a fluid bed reactor in accordance with the present invention; and

FIG. 2 is a longitudinal section of an advantageous embodiment of a fluid bed reactor in accordance with the present invention that can be'employed for decomposing metal carbonyls.

Generally speaking, the present invention contemplates improved fluid bed apparatus. The fluid bed reactor comprises a vertically disposed, elongated vessel that defines a lower fluidizing zone for confining a fluidized bed of particulate material and an upper particulate-material disengaging zone with the fluidizing zone having a lower heat exchange region and an upper particulate-material-treating region. The reactor is provided with inlet and outlet means for feeding and discharging particulate material to and from the fluidizing zone. The reactor is also provided with a fluidizing gas inlet for introducing fluidizing gas into the fluidizing zone vtofluidize particulate material contained therein. Heat exchange means are located in the heat exchange region of the fluidizing zone to maintain particulate material in the fluidizing zone at preselected temperatures. Fluid substances for treating particulate material is introduced into the treating region of the fluidizing zone by fluid inlet means so that the particulate material is treated by the fluid before being discharged into the disengaging zone without contacting the heat exchange means.

Referring now to the drawings which are merely for the purpose of illustrating the invention and not for limiting same, FIG. 1 is a schematic diagram of a fluid bed reactor in accordance with the present invention. Fluid bed reactor includes a vertically disposed elongated vessel 12 having a conically-shaped bottom 14. Vessel l2 and its bottom 14 can be made of mild steel provided that the reactants introduced into the fluidized bed are non-corrosive and/or are not heated to unduly high temperature. The nature of the reactants involved in the process will dictate the material out of which the vessel and other auxiliary equipment is made. Fresh particulate material stored in hopper 18 is fed to fluidized bed 16 via rotary valve 20 and particular material inlet port 22. Treated particulate material is removed from fluidized bed 16 via particulate material port 24 and valve 26 and is sent to product storage.

The apex of conically-shaped bottom 14 of reactor 10 is provided with a venturi tube 28 that is controlled by plugtype valve 30. Fluidizing gas is introduced to reactor 10 from a blower (not shown in the drawings) through pipe 32, independently controlled valve 34 and conduit 36.

As shown in FIG. 1, fluid bed reactor 10 defines a particulate material and gas disengaging zone A and a fluidizing zone B. Particulate material carried from fluidized bed 16 is disengaged from the fluidizing gas and carbon monoxide generated by the decomposition of metal carbonyl in zone A and drops back to fluidized bed 16. Within fluidizing zone B, which confines the fluidized bed 16, there is established an upper particulate-material-treating region C and a lower heatexchanging region D. Region D can be established by mounting heat exchange coils 38 in the lower portion of fluidized bed 16. Heat exchange coils 38 can be either cooling coils or heating coils that are made of, or coated with, an abrasion-resistant material. Treating region C is that portion of the fluidized bed 16 where particulate material is treated with fluid substances, as described in greater detail hereinafter. Fluid substances, from a source not shown in the drawings, are pumped, either in concentrated or diluted form, by pump 40 through valve 42 into fluidized bed 16 via fluid inlet 44 and outwardly and upwardly flaring nozzle 46. Since all gaseous reagents, including the fluidizing gas and the fluid substance, travel substantially upwardly, the fluid substance does not come in contact with heat exchange coils 38, and, therefore, the problems of deposition or of accretion on coils 38 heretofore encountered are avoided. Advantageously, nozzle 44 is concentrically mounted on the vertical axis of reactor 10 or at least a sufficient distance from the walls of the reactor to minimize accretion buildup thereon. As a further embodiment, fluid inlet 44 and nozzle 46 are constructed to be independently temperature controlled so that the fluid substance can be maintained either above or below the reaction temperature before it is discharged into fluidized bed 16.

Apparatus in accordance with the present invention is particularly useful for decomposing metal compounds that are heat decomposable to metal. Compounds that can be heat decomposed to metal include, although the invention is not limited thereto, the carbonyls of nickel, cobalt and iron, nitrosyls or nitrosyl carbonyls of copper and cobalt, hydrides of tin and antimony, and metal alkyls, such as chromyl chloride. If a reducing gas, such as hydrogen, is employed as the fluidizing gas, volatile halides of copper, nickel, cobalt and'iron can also be reduced in the apparatus of the present invention. Of course, the apparatus can be op erated with cooling coils so that fluid substances can be condensed and solidified upon particulate material in fluidized bed 16 to provide the cooled particulate material with a solidified coating.

The apparatus, however, presently finds its greatest use in the thermal decomposition of metal carbonyls, and'for this purpose the apparatus depicted in FIG. 2 is advantageously employed. Reactor 60 comprises a vertically disposed, elongated cylindrical mild steel shell 62, which as shown in FIG. 2, can consist of a plurality of cylindrical sections 64 having flanged ends 66. Sections 64 are assembled to provide a gas-tight chamber by placing gaskets 68 between flanges 66 before securing sections 64 with a plurality of bolts 70.

Reactor 60 is provided with a gas distribution plate 72 which can be multiperforate to insure uniform fluidizing gas distribution (not shown in the drawings) or can be constructed to receive fluidizing tuyeres 74 which function to provide uniform gas distribution while minimizing backflow of particulate material into plenum chamber 76. Fluidizing gas is introduced into plenum chamber 76 through port 78 from a source and a compressor not shown in the drawing. Particulate material that flows back to plenum chamber 76 is periodically removed through valved drain 80.

As described hereinbefore in conjunction with FIG. 1, a disengaging zone A and a fluidizing zone B are established in reactor 60 depicted in FIG. 2. In disengaging zone A after a large proportion of entrained particulate material has fallen back to fluidized bed 82, spent fluidizing gas is discharged through gas outlet 84 for further treatment to recover entrained particulate material and subsequent purification preparatory to being recycled to reactor 60.

When reactor 60 is employed to decompose metal carbonyls, heating region E and decomposing region F are established within fluidized bed 82 in fluidizing zone B. Heating coils 85, which can be abrasionresistant-coated, hollow tubes through which heated liquids or gases are passed or electrical resistance coils that are coated with an abrasion resistant material, are fixedly mounted in region E of fluidized bed 82. Metal carbonyls are introduced into the decomposing region F through water-cooled tuyere 86. Advantageously, heating region E and decomposing region F are volumetrically proportioned, taking into account the volume displaced by heating coils 85 in heating region E, so that the velocity of the fluidizing gas plus gases added and generated in situ in the decomposing region F is substantially equal to the velocity of fluidizing gas in the heating region E whereby flow of particulate material between these regions, and therefore heat control, is established. Seed material or particulate material to be coated is fed to fluidized bed 82 through solids port 88 from a hopper and feed valve not shown on FIG. 2. Product, either coated powder or metal powder, is withdrawn from fluidized bed 82 through product drain 90.

In employing the apparatus in accordance with the present invention, a lower heating region and an upper treating region is established in a fluidized bed of particulate material. The particulate material is heated to a preselected temperature in the heating region. A reing region at a temperature below it decomposition active vapor is introduced at a temperature below temperature. Advantageously, the gaseous metal carwhich it reacts into the treating region whereby the rebonyl is diluted with an inert gas, such as hydrogen or active vapor reacts with the particulate material in the carbon monoxide. It is most advantageous to use cartreating region without entering the heating region. 5 bon monoxide as the diluent gas since one of the prod- More specifically, when the apparatus in accordance ucts of reaction is carbon monoxide and subsequent with the present invention is employed for decompossteps to remove carbon monoxide from other diluents ing at least one metal carbonyl selected from the group is thereby not required. When diluting gaseous metal consisting of nickel, cobalt and iron, a fluidized bed of carbonyls with diluents, commercial production rates, particulate material, which can be of the metal being 10 process control and substantially complete decomposi decomposed or a particulate material to be coated, is tion are obtained by using metal carbonyl concentraestablished. A heating region is established in the lower tions in the range between about 100 grams p ta portion of the fluidized bed to heat the particulate madard cubic meter and 2,477 grams p standard cub c terial to at least the metal carbonyl decomposition temmeter, advantageously, metal carbonyl n nt ations perature. An upper decomposing region is established as high a p ss and even qu metal y s, ar

within the fluidized bed, and the metal carbonyl is inemployed to provide the highest possible production troduced into the decomp sin r i th h a t rates and to lower the risk of forming elemental carbon, cooled lance so that the metal carbonyl is decomposed partic larly when decomposing iron pentacarbonyl. on the particulate material that was heated in the heat- For t pu p s f giving those skill d in th art a ing region. When the process is d t d on a ti better appreciation of the advantages of the invention, uous basis, seed material or fresh material to be coated the following illustrative examples are given:

is continually added to the fluidized bed at a predetermined rate while product is removed from the fluidized EXAMPLE bed at a corresponding rate. Recycle of fines for seed A fluidized bed of 1,170 Pounds of nickel Particles material, as w ll as th r t t hi h t i l i were fluidized by 77 standard cubic feet per minute of moved from the reactor, is selected primarily to the bed carbon m n x d c mpr ss d to 14 pounds per square depth and not in response to heat requirements. inch gauge and preheated to 400F. in a reactor similar When decomposing at least one metal carbonyl of a to that depicted in FIG. 2 with a diameter 0f 14 inches. metal selected from the group consisting of nickel, co- A heating eg o a establ ed in the lower part of bait and iron, a fluidized bed of particulate material is the fl zing Zone by heat exchange tubes through formed and an upper decomposing zone and a lower which a heated organic fluid was passed t0 heat the fluheating zone are established within the fluidized bed. ldiled bed to 400F. In a decomposing region immedi- The particulate material in the decomposing region is ately above the heating region in the fluidized bed, 12 maintained atatemperature between about 300F. and standard cubic feet per minute of carbon monoxide 500F., advantageously 400F. to 450F., for nickel, containing 405 grams-of nickel per standard cubic and 400F. and 600F., advantageously 450F. and meter (16 percent nickel carbonyl by volume) was in- 525F., for iron. in most instances, these temperatures troduced into the fluidized bed through a water-cooled can be maintained by heating particulate material in tuyere. During a 12 hour operating period the nickel the heating region to a temperature between about carbonyl feed rate averaged 22 pounds of nickel per 25F. and 200F., advantageously between about 50F. hour, the organic fluid temperature averaged 471F. and l00F., (advantageously the temperature differenand the fluidized bed temperature averaged 422F. in tial for decomposing nickel carbonyl is 50F. and about the decomposing region and averaged 451F. in the 100F. for iron pentacarbonyl) above the temperature heating region. Effluent gases from the fluidized bed maintained within the decomposing region. When apcontained 2.0 grams of nickel per standard cubic meter paratus and process in accordance with the present infor a decomposition efficiency of 96.7 percent. During vention are employed in conjunction with an overall the test, 200 pounds of bed were removed and 46 process for forming a mixture of nickel and iron carpounds of minus 48 mesh fraction plus 10 pounds of bonyls, which mixture is collected in liquid iron pentaimpure nickel cyclone dust were added to the unit for carbonyl and then fractionally distilled, the metal carsize control. The chemical and physical analyses of the bonyls do not have to be completely decomposed, i.e., 50 ,seed and final bed are shown in Table I:

T ler Particle Size Wt Bulk Assa go 2 35 38 35 l00 20O Density +28 +35 +48 +65 +100 +200 +325 325 lbs/ft Seed 89.9 0.81 nil 0.3 0.4 0.8 33.5 60.3 3.4 1.3

Final Bed 99.1 0.08 0.05 22.5 47.8 19.7 8.7 1.2 0.1 0.05 355 less than 99 percent, e.g., less than percent, decom- EXAMPLE ll pos1t1on,smcethe off-gases can be employed for frac- This example confirms that iron particles can be tional distillation if iron pentacarbonyl is incompletely coated with a ferronickel alloy by employing the prodecomposed or collected in liquid iron pentacarbonyl 65 cess in accordance with the present invention.

if nickel carbonyl is incompletely decomposed. Gase- A fluid bed reactor, 14 inches in diameter, similar to ous metal carbonyl, advantageously fed through a that depicted in FIG.2 was equipped with electric resiswatercooled lance 86, is introduced to the decompostance heating coils. A fluidized bed of sponge iron was established with 995 pounds of particulate sponge iron which was fluidized with 40 standard cubic feet per minute of carbon monoxide compressed to 13 pounds per square inch gauge and preheated to 347F. The fluidized bed was heated to 500F. in the heating region within the fluidized bed prior to admitting 27.3 standard cubic feet per minute of carbon monoxide containing 120 grams nickel per standard cubic meter percent nickel carbonyl by volume) and 355 grams iron per standard cubic meter (15 percent iron pentacarbonyl by volume) through a water-cooled tuyere. During the operating period of 3% hours the feed rate averaged 56 pounds of nickel plus iron per hour, the temperature of the heating region averaged 590F. and the temperature of the decomposing region averaged 519F. The effluent gases exiting from the fluidized bed contained 0.31 grams iron per standard cubic meter and 0.05 grams nickel per standard cubic meter for decomposition efflciencies of iron and nickel of 99.7 and 99.9 percent, respectively. The chemical and physical analyses of the final bed are shown in Table II:

1. A process for decomposing at least one metal carbonyl in a fluidized bed which comprises: establishing, within a fluidized bed of particulate material, a lower heating region and an upper decomposing region; heating particulate material within the heating region to maintain the fluidized particulate material within the decomposing region above the metal carbonyl decomposition temperature; and introducing the metal carbonyl into the decomposing region to decompose the metal carbonyl on the heated particulate material in the decomposing region.

2. A process for decomposing at least one metal car- TA BLE TI Tvler Particle Size. Wt. Assay, 76 -88 -l00 "200 Ni C +48 +65 +100 +200 +325 -325 Final Bed 3.82 0.96 0.4 12.3 21.6 51.9 9.3 4.5

" iixlxitli tiii This example 001161 1115111 1111lfoh perltacal bfinyl 06.11

be decomposed in a fluid bed reactor similar to that depicted in FIG. 2. The reactor had an internal diameter of 5 inches and was provided with electrical resistance 35 heaters.

A fluidized bed of l 10 pounds of ferronickel plated sponge iron, prepared as described in Example 11, was fluidized by 6.1 standard cubic feet per minute of carbon monoxide. The fluidized bed was heated to 400F. by the electrical resistance heating elements prior to admitting 8.3 standard cubic feet per minute of carbon monoxide containing 152 grams iron per standard cubic meter (6.4 percent iron pentacarbonyl by volume) through a water-cooled tuyere. During an operating period of 48 hours, the feed rate averaged 5 pounds of iron per hour and the decomposing region of the fluidized bed averaged 440F. The effluent gases contained 6.3 grams iron per standard cubic meter for deof minus 65 mesh fraction plus 22 pounds of sponge iron seed were added to the unit for size control. The

plated iron contained 1.8 percent carbon on an overall balance. The chemical and physical analyses of the seed, final bed and product are shown in Table 111.

bohyl s e lec ted from the group consistmg ofnickelcarbonyl and iron pentacarbonyl in a fluidized bed which comprises establishing, within a fluidized bed of particulate material, a lower heating region and an upper decomposing region; heating particulate material within the heating region to maintain the temperature of the particulate material within the decomposing region at a temperature between about 300F. and 500F. when decomposing nickel carbonyl and between about 400F. and 600F. when decomposing iron pentacarbonyl; and introducing the metal carbonyl into the decomposing region through a water-cooled lance to decompose the metal carbonyl on the heated particulate material.

3. A process for decomposing nickel carbonyl in a fluidized bed which comprises: establishing, within a ;fluidized bed of particulate material, a lower heating region and an upper decomposing region, heating particulate material within the heating region to maintain the fluidized particulate material within the decomposing region at a temperature between about 400F. and 450F.; and introducing nickel carbonyl into the decomposing region to decompose the nickel carbonyl on the heated particulate material in the decomposing regen.

4. A process for decomposing iron pentacarbonyl in fluidized bed which comprises: establishing, within a fluidized bed of particulate material, a lower heating.

7 TABEE ITI T Tyler Particle Size, Wt, Bulk Assay, 7r 28 -35 48 l00 200 Density Ni C +28 +35 +48 +65 +200 +325 325 lbs/ft Seed 0.14 0:11 0.1 44.4 40.7 14.0 0.4 0.4 202 Final Bed 1.76 1.65 0.2 4.9 26.5 57.7 10.1 0.6 317 Prodduct 2.44 1.73 0.4 3.9 35.2 55.5 4.8 0.2 309 region and an upper decomposing region; heating particulate material within the heating region to maintain fluidized particulate material within the decomposing region at a temperature between about 450F. and 525F.; introducing iron pentacarbonyl into the decomposing region to decompose the metal carbonyl on the heated particulate material.

5. The process as described in claim 4 wherein the iron pentacarbonyl is introduced into the decomposing region as liquid iron pentacarbonyl to provide high production rates and to lower the risk of forming elemental carbon.

6. A method for decomposing at least one metal carbonyl in a fluidized bed retained in a fluid bed reactor equipped with heating means in the lowermost portion of the fluidized bed to form a heating region having a portion of its volume displaced by the heating means and with means for introducing metal carbonyl into the upper portion of the fluidized bed to form a decomposing region which method comprises establishing a fluidized bed of particulate material in the fluid bed reactor by introducing a fluidizing gas into the heating region of the fluidized bed, heating particulate material within the heating region to maintain the fluidized particulate material within the decomposing region above the metal carbonyl decomposition temperature; and introducing the metal carbonyl into the decomposing region to decompose the metal carbonyl on the heated particulate material in the decomposing region, the metal carbonyl being introduced into the decomposing zone in such a manner as to equalize substantially the velocity of gases, including generated carbon monoxide, in the heating and decomposing regions to promote conveyance of particulate material between the heating region and the decomposing region.

7. The method described in claim 6 wherein the metal carbonyl is at least one member selected from the group consisting of nickel carbonyl and iron pentacarbonyl and particulate material within the heating region is heated to maintain the temperature of the particulate material within the decomposing region at a temperature between about 300F. and 500F. when decomposing nickel carbonyl and between about 400F. and 600F. when decomposing iron pentacarbonyl.

8. The method described in claim 7 wherein the metal carbonyl is gaseous and is diluted with an inert gas.

9. The method described in claim 7 wherein the inert gas is carbon monoxide.

UNKTED STATES PATENT OFFECE QER'HMQAE GE l: EQ'HQN PATENT NO. 3 839,077

DATED i October 1, 1974 lNVENT0R( 1 RONALD DALE ROBINSON It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Signed and sealed this 15th day of July 1975.

(SEAL) Attest:

' C. MARSHALL DANN RUTH C" MASON Commissioner of Patents Attesting Officer and Trademarks Column 10, line 24 (Line 1 of Claim 9) for "7" read -=-8-=-, 

1. A PROCESS FOR DECOMPOSING AT LEAST ONE METAL CARBONYL IN A FLUIDIZED BED WHICH COMPRISES; ESTABLISHING, WITHIN A FLUIDIZED BED OF PARTICULATE MATERIAL, A LOWER HEATING REGION AND AN UPPER DECOMPOSING REGION; HEATING PARTICULATE MATERIAL WITHIN THE HEATING REGION TO MAINTAIN THE FLUIDIZED PARTICULATE MATERIAL WITHIN THE DECOMPOSING REGION ABOVE THE METAL CARBONYL DECOMPOSITION TEMPERATURE; AND INTRODUCING THE METAL CARBONYL INTO THE DECOMPOSING REGION TO DECOMPOSE THE METAL CARBONYL ON THE HEATED PARTICULATE MATERIAL IN THE DECOMPOSING REGION.
 2. A process for decomposing at least one metal carbonyl selected from the group consisting of nickel carbonyl and iron pentacarbonyl in a fluidized bed which comprises establishing, within a fluidized bed of particulate material, a lower heating region and an upper decomposing region; heating particulate material within the heating region to maintain the temperature of the particulate material within the decomposing region at a temperature between about 300*F. and 500*F. when decomposing nickel carbonyl and between about 400*F. and 600*F. when decomposing iron pentacarbonyl; and introducing the metal carbonyl into the decomposing region through a water-cooled lance to decompose the metal carbonyl on the heated particulate material.
 3. A process for decomposing nickel carbonyl in a fluidized bed which Comprises: establishing, within a fluidized bed of particulate material, a lower heating region and an upper decomposing region, heating particulate material within the heating region to maintain the fluidized particulate material within the decomposing region at a temperature between about 400*F. and 450*F.; and introducing nickel carbonyl into the decomposing region to decompose the nickel carbonyl on the heated particulate material in the decomposing region.
 4. A process for decomposing iron pentacarbonyl in a fluidized bed which comprises: establishing, within a fluidized bed of particulate material, a lower heating region and an upper decomposing region; heating particulate material within the heating region to maintain fluidized particulate material within the decomposing region at a temperature between about 450*F. and 525*F.; introducing iron pentacarbonyl into the decomposing region to decompose the metal carbonyl on the heated particulate material.
 5. The process as described in claim 4 wherein the iron pentacarbonyl is introduced into the decomposing region as liquid iron pentacarbonyl to provide high production rates and to lower the risk of forming elemental carbon.
 6. A method for decomposing at least one metal carbonyl in a fluidized bed retained in a fluid bed reactor equipped with heating means in the lowermost portion of the fluidized bed to form a heating region having a portion of its volume displaced by the heating means and with means for introducing metal carbonyl into the upper portion of the fluidized bed to form a decomposing region which method comprises establishing a fluidized bed of particulate material in the fluid bed reactor by introducing a fluidizing gas into the heating region of the fluidized bed, heating particulate material within the heating region to maintain the fluidized particulate material within the decomposing region above the metal carbonyl decomposition temperature; and introducing the metal carbonyl into the decomposing region to decompose the metal carbonyl on the heated particulate material in the decomposing region, the metal carbonyl being introduced into the decomposing zone in such a manner as to equalize substantially the velocity of gases, including generated carbon monoxide, in the heating and decomposing regions to promote conveyance of particulate material between the heating region and the decomposing region.
 7. The method described in claim 6 wherein the metal carbonyl is at least one member selected from the group consisting of nickel carbonyl and iron pentacarbonyl and particulate material within the heating region is heated to maintain the temperature of the particulate material within the decomposing region at a temperature between about 300*F. and 500*F. when decomposing nickel carbonyl and between about 400*F. and 600*F. when decomposing iron pentacarbonyl.
 8. The method described in claim 7 wherein the metal carbonyl is gaseous and is diluted with an inert gas.
 9. The method described in claim 7 wherein the inert gas is carbon monoxide. 